In the article entitled "Si MOSFET Fabrication Using Focussed Ion Beams" by R. L. Kubena et al I.E.E.E. Transactions on Electron Devices, Vol. ED-31, No. 9, September 1984, pages 1186 to 1189, there is described one specific example of a method of manufacturing a semiconductor device in which ions are implanted into a region of a semiconductor device body by deflecting in a pattern across a major surface of the body a beam of ions which are of sufficient energy to be implanted in the body. In the particular example described, source, drain and channel regions of a p channel depletion mode field-effect transistor (FET) are formed in an n type silicon body by implantation of boron ions from a source of boron and platinum with the platinum ions present in the beam being stopped by a trapping layer of aluminium at the body surface.
This I.E.E.E. Transactions article also describes the quite separate use of a beam of silicon ions from a gold-silicon liquid-metal-alloy source for ion-beam lithography to expose a layer of ion-sensitive resist in an area where a gate of an n channel enhancement mode field-effect transistor (FET) is to be formed from an underlying molybdenum or polycrystalline silicon layer on a thin silicon dioxide layer at a major surface of the device body. The non-exposed area of the layer of resist is removed by developing, and the exposure pattern is transferred into the underlying molybdenum or polycrystalline silicon layer by plasma or reactive ion etching so as to form a metal-on-oxide-on-semiconductor (MOS) insulated gate of the FET.